Bone marrow

Marrow is the fat inside the long bones, and for most of human history it was the most prized part of the animal. It is almost pure fat, mostly monounsaturated and saturated, with the connective tissue around it supplying the glycine muscle meat lacks.

In the 50 Man Foods it is the fat you spread on a hot potato instead of anything from a bottle.

  • Once or twice a week
  • 2 recipes
  • Organ and connective tissue
  • Updated Sep 2026

What it supplies

Nutrient · per 100 g, raw (two canoe-cut bones) Amount % DV Relative amount
Fat ~84 g 108%
Monounsaturated fat ~40 g 0%
Saturated fat ~28 g 140%
Protein 7 g 14%
Vitamin A trace 0%

Source: USDA FoodData Central and published composition data.Percent Daily Values are based on adult reference intakes. The bars stop at 100%; the numbers do not.

Why it works

The fat is the kind the body stores and burns cleanly — oleic and stearic acid — rather than the polyunsaturated fat that oxidises in tissue. It is also the most satisfying way to eat fat with a starch, which is how traditional diets paired the two.

A roast marrow bone is a meal that costs a few dollars, takes twenty minutes and displaces a seed-oil meal, which is most of what any of these foods do.

How much, how often

  • 2 bones

    Once or twice a week

    The fat with a starch — potato, rice or masa.

  • 230°C, 15–20 min

    Cut side up

    Soft and pulling from the bone, not melted into the tray.

How to buy and prepare it

Ask the butcher for canoe-cut femur bones — split lengthways — from grass-fed beef. Marrow should look pale pink to cream, not grey or brown. Bones sold for stock are usually cross-cut rounds; they roast fine but are harder to eat from.

Frozen bones are fine and are how most butchers keep them.

Roast at 230°C / 450°F for 15–20 minutes, cut side up, until the marrow is soft and slightly pulling from the bone but not melted away. Season with coarse salt. Spoon it onto a baked potato, into broth, or eat it with a spoon. The bones then go into the stockpot.

Raw bones keep two days in the fridge or six months frozen. Roasted marrow is best eaten at once; the fat solidifies and loses its texture when reheated.

Recipes that use it

In these guides

Questions

How often should I eat marrow?
Once or twice a week as the fat with a meal. There is nothing in it to overdose on; it is a question of how much fat the meal needs.
Is it safe to eat marrow from any bone?
Beef and lamb marrow from a butcher are the standard. Marrow from wild game is fine if the animal was healthy. Avoid bones from unknown sources for the same reasons you would avoid the meat.
Does marrow have stem cells?
Raw marrow contains living cells, but roasting kills them and eating them would not transfer anything. The value is the fat and the collagen around the bone.